def dict():
    xiaoming_dict = {'name': 'xiaoming'}
    xiaoming_dict['age'] = 18
    print(xiaoming_dict)
    print(len(xiaoming_dict))
    xiaoming_dict.setdefault('name', 'lele')  # 只做添加
    for k in xiaoming_dict:
        print(f'{k},{xiaoming_dict[k]}')  # fomat


dict()
